Airbus grooms five A400Ms for intense flight-test duties

With its first A400M in the air, Airbus Military is embarking on an intensive flight trials campaign, with the aim of clearing the baseline common standard aircraft (CSA) configuration for service in 2012. As political controversy surrounded the airplane, with Airbus threatening to stop funding, the flight test team made good progress. By the end of the fourth flight in mid-January, the normal operational flight envelope had been completely cleared.

Airbus is building five flight-test airframes to support the A400M, in addition to several ground rigs for testing fatigue and loads, hydraulics and systems, and avionics. The initial plan called for six flight-test aircraft, but one (MSN005) was cancelled to save costs.

Within the plan the five airframes have distinct primary tasks, but can also be used for secondary duties and to cover for other aircraft. MSN001, the first aircraft, is naturally dedicated to handling, envelope, flutter and loads testing. MSN002 is intended for detailed performance and certification trials, and tests of the defensive aids subsystem. MSN003 is the primary systems testbed for evaluation of the autopilot, navigation, fuel, electrics and other key systems.The fourth aircraft, MSN004, is to be the first fitted with a cargo system and provision for air-to-air refueling. It will focus on these areas accordingly. The last of the flying trials aircraft is MSN006, which is regarded as the first serial representative machine. It will be used to prove the maturity of systems, route proving and engine endurance trials.Test CampaignFormulation of a flight-test plan began in 2004. Delays to the overall program allowed Airbus to devise and install an impressive test infrastructure, based on what it had learned during testing of the A380 and MRTT tanker/transport. The main test centers are at Toulouse in France and Seville in Spain, the latter also being the assembly and delivery site. Both sites are integrated into a single test team so that flights can be followed from either center, using the same tools and a common database. Furthermore, real-time links have been established to other key A400M sites, such as Bremen in Germany and Filton in the UK, so that specialists can monitor flight trials without having to travel. Two flights can be monitored simultaneously.

Telemetry antennas cover most of France and Spain, and there is a mobile unit that can be deployed to other locations. The test fleet is expected to fly to many parts of the world to conduct both tests and demonstrations. Plans include cold weather testing at Kiruna (Sweden), Thule (Greenland), Iqaluit and Goose Bay (Canada). High-latitude tests will be conducted in Svalbard (Norway) and high crosswind tests at Keflavik (Iceland). Hot-weather trials will be conducted at Al Ain (UAE), hot and sandy at Tozeur (Tunisia), and hot and humid at Cayenne (Guyane). Further high-altitude trials will be performed in Bolivia and Colombia.

Tests also will be conducted at government-furnished test ranges throughout France, Germany, Spain, Turkey and the UK. Among them will be grass runway trials in Germany, soil runway tests in Spain, and low-level flying workload assessment (down to 150 feet) in the UK. The final phases of the paratroop tests will take place in Turkey, during which the A400M will carry 116 troops.

Overall, the initial flight test campaign is expected to total 4,370 hours, of which 1,850 hours are required for EASA type certification, and 2,520 hours for military certification and qualification. The latter is to be conducted by the procuring agency OCCAR through various joint panels representing the partner nations.

First Flight in December The official flight test campaign got under way on November 12 last year, when MSN001 was handed over to the flight-test department. During the following week the engines and APU were prepared after a period of storage. All four engines were started from the APU on November 19 and were run to full power the next day. Tests of a single Europrop TP400-D6 engine had previously been conducted on a C-130 Hercules.

Low-speed taxi trials, including 180-degree turns and reversing, began on November 23. Subsequent high-speed runs took the A400M up to the 120-knot takeoff speed. These tests revealed a number of minor problems, principally in the brakes and anti-skid system. An extra taxi run was required to test the fixes before the first flight could go ahead.

Adverse weather caused some delay to the first flight, as MSN001 has instrumented propeller blades on engines one and two. The delicate and expensive instrumentation is highly susceptible to precipitation damage, so good weather was needed for both ground and air tests.

This problem has continued into the new year, with unusually wet weather in southern Spain.

All was well on December 11 and MSN001 took off from Seville’s San Pablo Airport at 10:15 a.m. local. The first flight was undertaken with Airbus Military’s chief test pilot Ed Strongman in the left seat and Ignacio Lombo in the right seat. Four flight test engineers were also onboard to monitor systems.

The flight began with a commendably short takeoff run and sprightly climbout, before Strongman and his crew put the aircraft through a series of maneuvers with various flap configurations and at various speeds. The landing gear was cycled several times, and MSN001 returned to Seville after three hours and 47 minutes airborne.

The A400M flew again on December 22 and by the end of the three-hour sortie the complete normal envelope had been opened. This included altitude up to 30,000 feet, speed down to stall warning with and without flaps, maximum operating speed of 300 knots and maximum operating Mach number of 0.72. This was accomplished in both direct and normal control laws.

MSN001 flew for a third time on January 7, a two-hour 25-minute sortie that further explored handling. Michel Gagneaux became the third pilot to fly the aircraft, supporting “Nacho” Lombo. The fourth flight lasted nearly five hours.

Ongoing TestsFollowing initial testing at Seville, MSN001 is to become one of three A400Ms based at Toulouse, from where it will conduct around 1,200 hours testing. It is in the “heavy” instrumentation configuration, with between 14 and 16 metric tons of test equipment aboard. MSN002 is rapidly nearing completion, and will also be in “heavy” layout. It is due to join the test fleet in March and will fly 1,100 hours from Seville. Aircraft 3 will have less flight test instrumentation (“medium FTI”) and is due to fly 975 hours from Toulouse after a scheduled first flight in May.

At the end of the year, a second medium FTI aircraft (MSN004) is scheduled to begin 870 test hours from the base at Seville. MSN006, the production-representative aircraft is due to fly with only “light” instrumentation and is to fly 225 hours from Toulouse beginning in July 2011.

Airbus Military has orchestrated an intensive campaign, with up to two flights a day from Monday to Friday. Regular maintenance will be performed overnight and during weekends. In the current outlook, there are no planned lay-ups, or interruptions of the test program, for further modifications.

European certification for the common standard aircraft (cargo transport) is targeted for the end of November 2011, and first production aircraft delivery scheduled for the end of 2012. Airbus Military is offering a staged introduction of the aircraft’s capabilities. Further testing will be required to certificate various customer options, including tanker capability.